1. Field of the Invention
This invention is related to a fan duct, and particularly to a fan duct corresponding to a heat sink.
2. Description of Prior Art
Electronic devices such as central processing units (CPUs) frequently generate large amounts of heat during normal operation, therefore a heat dissipation assembly is used to dissipate heat from the electronic device. Conventionally the heat dissipation assembly comprises one or more pairs of heat sinks and fans. The bottom surface of a heat sink is attached to an electronic device, while the top surface form thereon a plurality of fins defining a plurality of channels therebetween. A fan is installed at one side of the fins for producing airflow through the channels to accelerate heat convection. However, in above cases, there produce refluence of heat airflow constantly.
In order to prevent producing refluence of heat air flow, a cylindrical fan duct is used. The fan duct comprises a cylinder. One end of the cylinder hoods the top of a fan, while the other end is attached to a computer case. The computer case defines a plurality of apertures corresponding to the fan. In operation, outside cooling air flows through the fan duct to blow to the heat sink or hot air from the heat sink flows away from the computer case via the fan duct, thereby preventing producing refluence of heat air flow. The height of the fan duct is fixed and only fits a kind of special computer cases whose height is fixed or whose inner space is fixed. However, there are so many kinds of computer cases which have a different height or inner space. Therefore, there needs a fan duct which can adapt to computer cases with different heights or inner space.